1. Field of the Invention
The invention relates generally to machine tools for cutting grooves in a hole previously formed in a workpiece and, more particularly, to an insert for use in machining grooves within a bore.
2. Background Information
It is often necessary or desirable to create an internal recess or groove within a tube or hole of a machine part. Such grooving process is typically carried out in one of two ways. One solution is to use a grooving tool attached to a tool holder on a single axis rotary drive. The end of the grooving tool that is placed in the hole has one or more cutting inserts. These cutting inserts are often radially extendable and retractable. Such feature allows the tool to be inserted into a hole, then rotated and extended radially to form the groove along the inside surface of the hole.
Examples of such extendable inserts are well known in the prior art. U.S. Pat. No. 2,333,935 and U.S. Pat. No. 2,545,443 each shows extendable inserts for internal grooving. Generally, a central rod is moved in an axial direction and has a tapered surface at its end. The tapered surface engages one or more cutting inserts in a wedging action to convert the axial force into a radial force moving the insert into cutting position. The means for moving the central rod is often mechanical, but electrical or hydraulic movement of such a rod is not new to the art. Regardless of the means for effecting movement, an elaborate control system is generally required to control the movement of the central rod. This control is necessary because the position of the central rod determines the diameter of a cut that will be made in the wall of the workpiece.
Another solution, such as described in commonly assigned U.S. patent application Ser. No. 13/159,901, utilizes a solid bodied cutting tool body having a number of pockets in which cutting inserts having a desired cutting profiled are installed. In order to carry out grooving operations on the wall of a bore of a workpiece, tool body is both rotated about a central axis while simultaneously interpolated along a generally circular path about the central axis of the bore.
Regardless of the solution, each utilizes one or more replaceable cutting inserts of a selected profile. Ideally, such cutting inserts are durable, capable of forming the desired grooves in a timely manner, and capable of forming grooves of a desired quality. Although known cutting inserts have been generally suitable for such operations, there exists a need for improved cutting inserts for use in such groove cutting operations.